Quote:
Originally Posted by Apex1.0
I am looking for a 135i for a weekend fun and occasional track car. The idea was to throw some M3 bits and coilovers, and go FBO for some power on the street and track. Probably look at about 5k miles per year and I have a lift and can pretty much do all work myself.
Initially I wanted a twin turbo car, because well it is a twin turbo plus 400rwhp on pump gas seems pretty common. I am not worried about the HPFP issues, but I do want something that can be reliable at the track. That is why I expect to have two maps, a max effort street map (400rwhp ish) and a consistent track map (300rwhp ish).
The issue is most of the clean 1 series I see with the options I want are N55. So I know I will be giving up FBO power with a N55, but supposedly they are more reliable? What does that mean? What are the advantages of the N55? Transmission will be 6 speed either way.
Why do I want a N55?
|
FBO N55's will see around 380 whp on an E30 blend compared to around 420 whp with an N54. The biggest difference between the two motors is low end torque. Obviously the N54 makes more top end power, but it does not have the same initial punch that the N55 does. I have driven 335's with N54's and N55's and that has been my observation. One thing to note as well is BMW changed the HPFP to a plunger style in 2012 on N55's that does not flow as well when you start running E85.
N55's have proven to be more reliable than N54's so far, but aren't without their problems. N55 fixed wastegate rattle and a few others that I can't think of at the moment, but issues like the electric water pump going out and OFHG replacement still remain.
Even so, if you are proactive and not reactive about maintenance on these engines, you will have a good owners experience.